IncidentalFindingsonConeBeamComputed TomographyImagesdownloads.hindawi.com/journals/ijd/2012/871532.pdf · 2019-07-31 · Simple bone cyst 3 4 7 Residual cyst 3 4 7 Dentigerous cyst

Hindawi Publishing CorporationInternational Journal of DentistryVolume 2012, Article ID 871532, 9 pagesdoi:10.1155/2012/871532

Research Article

Incidental Findings on Cone Beam ComputedTomography Images

Veeratrishul Allareddy,1 Steven D. Vincent,1 John W. Hellstein,1 Fang Qian,2

Wendy R. K. Smoker,3 and Axel Ruprecht1

1 Department of Oral Pathology, Radiology, and Medicine, The University of Iowa, 801 Newton Road, Iowa City, IA 52242, USA2 Department of Preventive and Community Dentistry, 801 Newton Road, Iowa City, IA 52242, USA3 Department of Radiology, The University of Iowa, 200 Hawkins Drive, Iowa City, IA 52242, USA

Correspondence should be addressed to Veeratrishul Allareddy, [email protected]

Received 29 August 2012; Revised 15 October 2012; Accepted 31 October 2012

Academic Editor: Yasuhiro Morimoto

Copyright © 2012 Veeratrishul Allareddy et al. This is an open access article distributed under the Creative Commons AttributionLicense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properlycited.

Background. Cone beam computed tomography (CBCT) has gained widespread acceptance in dentistry for a variety ofapplications. Most dentists who are not radiologists/trained in radiology are generally not familiar with interpretation ofanatomical structures and/or pathosis outside their area of primary interest, as often this was not within the scope of their training.Objectives. To assess that the number of incidental findings on a CBCT scan is high both within and outside of the primary area ofinterest, thereby emphasizing the importance of interpretation of all areas visualized on the scan. Materials and Methods. An oraland maxillofacial radiologist reviewed 1000 CBCT scans (382 males and 618 females) for findings both in- and outside the areaof interest. Results. Of the 1000 subjects that were reviewed, 943 scans showed findings in the primary regions of interest and/oroutside the regions of interest, and 76 different conditions were visualized in these scans both in and outside the areas of interest.Conclusion. From the wide scope of findings noted on these scans, it can be concluded that it is essential that a person trained inadvanced interpretation techniques in radiology interprets cone beam computed tomography scans.

1. Introduction

The development of panoramic radiography in the 1950s andits commercial introduction in 1965 led to the widespreadadoption and use of the technology. Although widely used,these images have the same inherent limitations as other2D projections, namely, magnification and minification ofstructures, superimposition of anatomical and/or patholog-ical entities, and misrepresentation of structures. Howeverpanoramic radiography is efficient at providing an overviewof oral and maxillofacial hard tissues, including teeth, andmay reveal associated pathoses of the jaws. To overcome someof the above limitations cone beam computed tomography(CBCT) for the jaws was developed in the 1990s and isgaining widespread acceptance in dentistry, especially in thelast 5 years.

CBCT was initially developed for angiography and isalso popularly used for radiotherapy guidance and mam-mography [1] as an alternative to conventional fan beamhelical computed tomography (CT) machines to providemore rapid acquisition of a dataset of the entire field ofview. This rapid acquisition has enabled less movement inpatients during the process of acquisition of the images. Inaddition, the radiation dose to the patient is lower thanthat of conventional CT machines and CBCT machines aremarkedly less expensive than conventional CT machines.

However, there are disadvantages. The field of view isusually smaller than that of standard CT and there is a lackof differentiation among various soft tissues.

CBCT scanners were first introduced in 1997 in Italy[2]. Cone beam computed tomography scanners have beencommercially available since 2001 in the United States [3].

2 International Journal of Dentistry

Table 1: Age and Sex distribution of subjects.

Age groupNumber of subjects

Males Females Total

5 years and 11 months–10 12 13 25

11–20 78 101 179

21–30 21 30 51

31–40 29 62 91

41–50 53 94 147

51–60 86 134 220

61–70 64 133 197

71–80 35 44 79

81–87 4 7 11

Total 382 618 1000

Table 2: Table showing why CBCT scans were made on the subjects.

Reason for Scan No of Subjects

Implants/Bone evaluation for implants 678

Impaction localization 110

Orthodontic records 67

Other possible pathosis 46

Evaluation of graft in the sinuses area/bone assessment for implants 40

Supernumerary teeth localization 31

Sinus evaluation prior to implants 17

TMJ assessment 11

Total 1000

CBCT is used in dentistry for a variety of applicationssuch as

(i) evaluation of pathosis in the jaws,

(ii) evaluation of bone for implants,

(iii) orthodontic assessments,

(iv) tmj assessments, and

(v) endodontic assessments.

This imaging modality is mainly for the osseous anddental components of the maxillofacial complex.

Most dentists who are not radiologists are not familiarwith interpretation of anatomical structures and/or patho-sis outside the area of primary interest. This study wasundertaken to determine the prevalence and nature ofunusual findings in and around the maxillofacial complexencountered in CBCT studies.

2. Aim

To assess whether the number of incidental findings on aCBCT scan is high inside and outside the primary areasof interest as well, thereby emphasizing the importance ofinterpretation of all areas visualized on the scan.

3. Materials and Methods

3.1. Source of the Scans. The CBCT scans (Table 2) used inthe study were acquired on an i-CAT machine (ImagingSciences International, Hatfield, PA). To assess the feasibilityof this study, a pilot survey was carried out on a sequentialseries of 100 subjects scanned at a private imaging company.Institutional Review Board approval to use the informationon the scans for the study was obtained at The University ofIowa. Once the data obtained from the initial 100 subjectsshowed the feasibility and importance of a comprehensivestudy, a series of 1000 subjects who were imaged at thesame company were analyzed comprehensively. Consent wasobtained from all the subjects as well as the private imagingcompany to use and share the information from the scan forpurposes of education, including for teaching and research.

3.2. Field of View of the Scans. All the scans used for thisstudy were acquired at a field of view of 13 cm and a 0.3 mmthickness.

3.3. Time of Exposure to Acquire the Scan. The time ofexposure to acquire the scan was uniform at 8.5 seconds for843 subjects and 20 seconds for 157 subjects after acquiringthe scout image to assess and adjusted for proper positioningof the subject to include the region of interest in the scan. Thefield of view and thickness of the slices remained the same inboth sets of subjects despite the change in scan time from 20

International Journal of Dentistry 3

Table 3: Summary of all the findings seen in the 1000 scans (318 males and 682 females).

Findings Visualized Male Female Total

Variations in size, shape, and number of teeth

Oligodontia 16 22 38

Supernumerary teeth 19 12 31

Transposition 2 3 5

Compound Odontoma 0 4 4

Microdontia 3 1 4

Dentin dysplasia 1 1 2

Dentinogenesis imperfecta with osteogenesis imperfecta 0 1 1

Amelogenesis imperfecta 1 0 1

Taurodontism 1 0 1

Gemination 1 0 1

Macrodontia 1 0 1

Periapical/parapical/peridental findings

Rarefying osteitis 114 167 281

Enostosis 54 82 136

Graft material and sclerotic healing 35 73 108

Root fragments 45 55 100

Impactions (not including third molars) 29 37 66

Restorative material in the periapical regions of teeth 22 37 59

External resorption 22 20 42

Sclerosing osteitis 6 11 17

Oroantral fistulas 6 8 14

Hypercementosis 5 8 13

Cemento-osseous dysplasia 1 9 10

Hyperplastic dental follicle 3 5 8

Fibrous dysplasia 4 4 8

Simple bone cyst 3 4 7

Residual cyst 3 4 7

Dentigerous cyst 4 2 6

Osteosclerosis 2 3 5

Cementoblastoma 2 2 4

Nasopalatine canal cyst 3 0 3

Reactive hyperplastic osteitis 0 2 2

Keratocystic odontogenic tumor 1 1 2

Giant cell lesion 1 0 1

Osteomyelitis 1 1 2

Radioosteonecrosis 0 1 1

Chemoosteonecrosis 0 1 1

Pathosis/anatomical variants in the paranasal sinuses

Mucositis/sinusitis/mucous retention pseudocysts 246 305 551

Surgical changes in the sinuses 13 16 29

Hypoplastic sinuses 8 13 21

Osteoma 1 3 4

Findings in cervical vertebrae region

Osteoarthrosis 90 150 240

Osseous screws in vertebrae 1 2 3

Fusion of C2-3 cervical vertebrae 1 0 1

Nonsegmentation of C2-3 vertebrae 1 0 1

Findings in the TMJs region/associated structures

Osteoarthrosis 42 116 158

Coronoid hyperplasia 8 9 17


Table 3: Continued.

Findings Visualized Male Female Total

Condylar hyperplasia 1 2 3

Condylar hypoplasia 2 0 2

Calcifications visualized in the volume

Pineal gland calcifications 43 104 147

Tonsilliths 53 39 92

Carotid artery calcifications 28 29 57

Osteoma cutis 9 14 23

Sialoliths 1 3 4

Vertebral artery calcification 0 1 1

Other dystrophic calcifications

Temporal regions 1 2 3

Adenoids 1 1 2

Epiglottis 1 1 2

Other findings

Adenoidal hyperplasia 44 63 107

Soft tissue swellings in the airway region 2 7 9

Palatal tori 1 7 8

Cleft palate 4 1 5

Shot gun wound 0 4 4

Hair artifacts 0 4 4

Hearing aids 1 3 4

Osteopenia 1 3 4

Retained suture material in the jaws 2 2 4

Nose ring 0 3 3

Earrings 0 3 3

Malignancy 2 1 3

Stafne defect 2 1 3

Mandibular hemihyperplasia 2 0 2

Unhealed fracture 1 0 1

Surgical drain in the soft tissue of brain 1 0 1

Surgical staples in the neck 1 0 1

Nut notch 1 0 1

Implant impinging on borders of the inferior alveolar canal 1 0 1

(a) (b) (c)

Figure 1: An impacted mesiodens (arrows) angulated obliquely such that the crown is towards the floor of the nasal cavity and the rootbetween the roots of the central incisors of the maxilla is seen in this MPR image.


(a) (b) (c)

Figure 2: A Compound odontoma (arrows) made of multiple small tooth like entities seen in the facial aspect of the mandibular left secondpremolar and molar regions as seen in the mandible on these MPR images.

Figure 3: Florid cemento-osseous dysplasia seen as mixed predominantly radiolucent lesions seen in the periapical regions of most of theteeth in the maxillae and the mandible on this panoramic reconstruction image.

seconds to 8.5 seconds. The decrease in time of acquisitionwas due to the increased image acquisition speed of a newsensor. The field of view and the slice thickness remained thesame for all the subjects.

3.4. Age and Sex Distribution of Subjects. The age range ofsubjects is 5 years and 11 to 87 years. See Table 1 for the entirelist of ages of the subjects.

3.5. Reasons for the Scan. The subjects scanned presented fora variety of reasons given in Table 1

3.6. Interpretation and Review of the Scans. An oral andmaxillofacial radiologist (VA), using the proprietary i-CATviewer software version 3.034, reviewed the images. If therewas any doubt on any of the findings, other authors wereconsulted for their opinion.

4. Results

Table 3 represents the pathologic entities and/or anatomicvariants found inside and out of the primary region ofinterest. For convenience they have been grouped intodifferent headings in the table.

Eighty nine subjects had variations in size, shape, andnumber of teeth. Amongst these subjects the most commonfinding was missing teeth (38 subjects). The other morecommon finding was the presence of supernumerary teeth(31 subjects) (Figure 1). Transposition (5 subjects), com-pound odontomas (Figure 2) (4 subjects), microdontia (4subjects) were the other relatively common findings. It wasinteresting to note that rare entities like dentin dysplasia(2 subjects), dentinogenesis imperfecta (1 subject), amel-ogenesis imperfecta (1 subject) were encountered amongstthe scans reviewed. Taurodontism (1 subject), gemination(1 subject), and macrodontia (1 subject) were the otherconditions encountered amongst these patients as far asvariations in shape and size of teeth were concerned.

The most common findings (783) were peridental inlocation. Periapical rarefying osteitis (281 subjects) was the


(a) (b) (c)

Figure 4: A dentigerous cyst (arrows) seen as well defined radiolucent entity around the crown of the impacted and displaced maxillary leftthird molar and is encroaching into the left maxillary sinus in these MPR images.

(a) (b) (c)

Figure 5: A nasopalatine canal cyst (arrows) is seen as a well-defined radiolucent entity in the maxilla in the midine in the regions of thenasopalatine canal. The inferior borders of this entity are not visualized.

most common finding followed by enostosis (136 sub-jects), graft material and/or sclerotic healing (108 subjects),retained root fragments both from deciduous and perma-nent teeth (100 subjects), impactions not including thirdmolars (66 subjects), restorative material in the periapicalregions of teeth (59 subjects), and external resorption (42subjects). Relatively fewer common findings included scle-rosing osteitis (17 subjects), oroantral fistula (14 subjects),hypercementosis (13 subjects), cemento-osseous dysplasia(Figure 3) (10 subjects), hyperplastic dental follicle (8 sub-jects), simple bone cyst (7 subjects), residual cyst (7 subjects),dentigerous cyst (Figure 4) (6 subjects), idiopathic osteoscle-rosis (5 subjects), cementoblastoma, (4 subjects), nasopala-tine canal cyst (3 subjects) (Figure 5), reactive hyperplasticosteitis (2 subjects), keratocystic odontogenic tumor (2subjects), osteomyelitis (2 subjects), and osteonecrosis bothradiation induced (1 subject) and bisphosphonate induced(1 subjects).

The paranasal sinuses were the location of the nextcommon findings (605 findings). Mucositis/sinusitis/mucusretention pseudocysts (grouped as one category) were themost common findings (551 subjects). Surgical changes (29

subjects), hypoplastic sinuses (21 subjects) and osteoma inone of the paranasal sinuses (4 subjects) were the otherfindings in the paranasal sinuses.

Osteoarthrosis (240 subjects) was the most commoncondition found in the cervical vertebrae. Osseous screws (3subjects), fusion of cervical vertebrae (1 subject) and non-segmentation of C2-3 vertebrae (1 subject) were the otherfindings visualized in the vertebrae.

Osteoarthrosis (158 subjects) was also the most commoncondition found in the TMJs and associated structures.Coronoid hyperplasia (17 subjects), Condylar hyperplasia (3subjects) and condylar hypoplasia (2 subjects) accounted forthe other findings in the TMJs region.

Pineal gland calcifications (147 subjects), tonsilliths (92)subjects were the most common findings amongst thedifferent calcifications seen. Carotid artery calcifications(Figure 6) (cervical and/or intracranial calcifications—57subjects) were the most significant amongst the differentcalcifications visualized in these scans. Males (28 of the 382subjects) had a significantly higher percentage of carotidartery calcifications when compared to females (29 of the 618subjects). Osteoma cutis (23 subjects), sialoliths (4 subjects)


(a) (b) (c)

Figure 6: Carotid artery calcifications (arrows) seen as multiple small radiopaque linear entities taking the outline of the shape of a vessel inthe cervical regions on these MPR images.

(a)

(b)

Figure 7: An anterior Stafne defect (ASD) seen as a well-defined area of scooped out bone in the region of the sublingual salivary gland onthe right side of the lingual aspect of the mandible on these MPR (arrows) and 3D images.

and vertebral artery calcification (1 subjects), and a varietyof dystrophic calcifications including in the temporal regions(3 subjects), adenoids (2 subjects), and epiglottis regions (2subjects), were the other calcifications encountered in thesescans.

There was a variety of other findings that were notgrouped into any particular category in our study. Adenoidalhyperplasia (107 subjects) was the common other finding.There were also soft tissue swellings (9 subjects) in theairway regions other than in the adenoids. Large palatal tori

(8 subjects), cleft palate (5 subjects), shot gun wound (4subjects), hair artifacts (4 subjects), hearing aids (4 subjects),osteopenia (4 subjects), retained suture material in the jaws(4 subjects), nose rings (3 subjects), earrings (3 subjects),malignancy (3 subjects), Stafne defect (Figures 7(a) and7(b)) (3 subjects), mandibular hemihyperplasia (Figure 8)(2 subjects), surgical drain in the soft tissue of the brain (1subject), surgical staples in the neck (1 subject), nut notch(1 subject), and an implant impinging on the borders of theinferior alveolar canal (1 subject).


Figure 8: Hemihyperplasia seen as a much larger right side of the mandible on this panoramic reconstruction CBCT image.

(a) (b) (c)

Figure 9: A malignancy seen as a soft tissue mass (arrows) in the sella region, which is causing extensive destruction in the osseouscomponents of the bone in the sella region and encroaching into the adjacent areas on these MPR images.

The most significant of all these findings were threemalignancies (2 males and 1 female) found incidentally. Onein the sella region had caused extensive destruction of thesella turcica (Figure 9), two subjects had metastatic lesionsin the mandible, one from the prostate and one from breast(Figure 10).

5. Discussion

Of the 1000 scans that were reviewed only 57 had no osseouspathosis or incidental findings. 943 scans showed findings inthe primary regions of interest and/or outside the regions ofinterest and 77 different conditions were visualized in thesescans both in and outside the areas of interest. Often thescans had incidental findings in more than one area. Thepercent of incidental findings in our study (94.3) was similarto that of the the other studies done by Caglayan and Tozoglu[4] (92.8%) and Price et al. [5] [90.7%] and greater than thestudy by Cha et al. (24.5%) [6].

One of the advantages of the current study whencompared to other studies like Price et al. is that in thosesubjects in whom there were diseases that were requiredfollowing biopsy, the findings in the original report werecompared with findings from the histopathological eval-uation and the prevalence of the different diseases wasbased on the histopathological confirmation of the radiologicinterpretation. This step the authors believe was the mostsignificant when compared to other studies that evaluated

incidental findings and had mentioned that this was one ofthe short comings of their study (Price et al.).

Our study is the largest study looking at incidentalfindings using 1000 subjects compared to the studies byPrice et al. (300 cases), Caglayan and Tozoglu (207 cases),Cha et al. (500 cases), and Pette et al. [7] (318 cases).Such a large sample provides a better clarification of theimportance of reviewing CBCT scans thoroughly as signif-icant diseases such as malignancies and also those diseasesthat are relatively rare are more likely to be included inthe sample size, for example, the malignancy cases whichwere the most significant and immediately life threateningto the subjects. Our study also compares well with currentpublished manuscripts by Pliska et al. [8] and Rogers et al. [9]and Pazera et al. [10] which all looked at incidental findingson CBCTs made on orthodontic patients. The advantage ofour study in comparison to the above studies is that there is agreater likelihood of finding diseases when a wider age groupof patients was included.

Some of the drawbacks of our study were that asingle oral and maxillofacial radiologist reviewed all theimages predominantly, although others were available forconsultation. One of the other drawbacks of our study wasthat it included almost one half times (382 males to 618females) the number of female subjects when compared tothe males. It makes comparison of prevalence of variousdiseases somewhat more difficult than if there were equalnumber of subjects.


Figure 10: A metastatic lesion seen as multiple poorly defined radiolucent areas (arrows) in the right side of the mandible causing loss ofthe cortical borders of the right inferior alveolar canal on these axial, panoramic, and orthoradial images.

6. Conclusions

From the wide and comprehensive scope of findings foundinside and outside the primary areas of interest in the 1000subjects, it can be concluded that it is essential that a persontrained in advanced interpretation techniques in radiologyinterprets CBCT scans. It can also be concluded that theseCBCT images need to be reviewed comprehensively.

Acknowledgment

The author acknowledge 360 Imaging, Atlanta.

References

[1] W. C. Scarfe and A. G. Farman, “What is cone-beam CT andhow does it work?” Dental Clinics of North America, vol. 52,no. 4, pp. 707–730, 2008.

[2] P. Mozzo, C. Procacci, A. Tacconi, P. Tinazzi Martini, and I. A.Bergamo Andreis, “A new volumetric CT machine for dentalimaging based on the cone-beam technique: preliminaryresults,” European Radiology, vol. 8, no. 9, pp. 1558–1564,1998.

[3] W. C. Scarfe, A. G. Farman, and P. Sukovic, “Clinical applica-tions of cone-beam computed tomography in dental practice,”Journal of the Canadian Dental Association, vol. 72, no. 1, pp.75–80, 2006.

[4] F. Caglayan and U. Tozoglu, “Incidental findings in the max-illofacial region detected by cone beam CT,” Diagnostic andInterventional Radiology, vol. 18, no. 2, pp. 159–163, 2012.

[5] J. B. Price, K. L. Thaw, D. A. Tyndall, J. B. Ludlow, and R.J. Padilla, “Incidental findings from cone beam computedtomography of the maxillofacial region: a descriptive retro-spective study,” Clinical Oral Implants Research, vol. 23, no. 11,pp. 1261–1268, 2012.

[6] J. Y. Cha, J. Mah, and P. Sinclair, “Incidental findings in themaxillofacial area with 3-dimensional cone-beam imaging,”American Journal of Orthodontics and Dentofacial Orthopedics,vol. 132, no. 1, pp. 7–14, 2007.

[7] G. A. Pette, F. J. Norkin, J. Ganeles et al., “Incidental findingsfrom a retrospective study of 318 cone beam computedtomography consultation reports,” The International Journalof Oral and Maxillofacial Implants, vol. 27, no. 3, pp. 595–603,2012.

[8] B. Pliska, M. DeRocher, and B. E. Larson, “Incidence of sig-nificant findings on CBCT scans of an orthodontic patientpopulation,” Northwest Dentistry, vol. 90, no. 2, pp. 12–16,2011.

[9] S. A. Rogers, N. Drage, and P. Durning, “Incidental findingsarising with cone beam computed tomography imaging of theorthodontic patient,” Angle Orthodontist, vol. 81, no. 2, pp.350–355, 2011.

[10] P. Pazera, M. M. Bornstein, A. Pazera, P. Sendi, and C.Katsaros, “Incidental maxillary sinus findings in orthodonticpatients: a radiographic analysis using cone-beam computedtomography (CBCT),” Orthodontics and Craniofacial Research,vol. 14, no. 1, pp. 17–24, 2011.

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IncidentalFindingsonConeBeamComputed TomographyImagesdownloads.hindawi.com/journals/ijd/2012/871532.pdf · 2019-07-31 · Simple bone cyst 3 4 7 Residual cyst 3 4 7 Dentigerous cyst